#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b,c,d;
	cin>>a>>b>>c>>d;
	if(a>b&&a>c&&a>d){
		cout<<a;
	}if(b>a&&b>c&&b>d){
		cout<<b;
	}if(c>a&&c>b&&c>d){
		cout<<c;
	}if(d>a&&d>b&&d>c){
		cout<<d;
	}
}
/**************************************************************
	Problem: 1305
	User: sucongyi
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2072 kb
****************************************************************/